/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 蒋健
 * Date: 2022-01-23
 * Time: 21:06
 */
public class MyCircularQueue {
    public int[] elem;
    public int front;//队头下标
    public int rear;//队尾下标

    public MyCircularQueue(int k) {
        this.elem = new int[k+1];
    }

    /**
     * 入队
     *
     * @param value
     * @return
     */
    public boolean enQueue(int value) {
        if (isFull()) {
            return false;
        }
        this.elem[rear] = value;
        rear = (rear + 1) % this.elem.length;
        return true;
    }

    /**
     * 获取队头元素
     *
     * @return
     */
    public int Front() {
        if (isEmpty()) {
            return -1;
        }
        return elem[front];
    }

    public int Rear() {
        if (isEmpty()) {
            return -1;
        }
        int index = -1;
        if (rear == 0) {
            index = elem.length - 1;
        } else {
            index = rear - 1;
        }
        return elem[index];
    }

    public boolean isEmpty() {
        return front == rear;
    }

    public boolean deQueue() {
        if (isEmpty()) {
            return false;
        }
        front = (front + 1) % elem.length;
        return true;
    }

    public boolean isFull() {
        //rear的下一个是front
        if ((this.rear + 1) % elem.length == front) {
            return true;
        }
        return false;
    }
}
